I've fixed the patch just now. It works and pass the regression test ;-)
Here is the new patch. I'll keep the hash code  in order and use
binary search in a later version soon.


diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index 6a5c000..1a8dc75 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -129,7 +129,11 @@ hashbuildCallback(Relation index,
        IndexTuple      itup;

        /* form an index tuple and point it at the heap tuple */
+#ifdef HASHVALUE_ONLY
+    itup = _hash_form_tuple(index, values,isnull);
+#else
        itup = index_form_tuple(RelationGetDescr(index), values, isnull);
+#endif
        itup->t_tid = htup->t_self;

        /* Hash indexes don't index nulls, see notes in hashinsert */
@@ -171,7 +175,12 @@ hashinsert(PG_FUNCTION_ARGS)
        IndexTuple      itup;

        /* generate an index tuple */
+#ifdef HASHVALUE_ONLY
+    itup = _hash_form_tuple(rel, values, isnull);
+#else
        itup = index_form_tuple(RelationGetDescr(rel), values, isnull);
+#endif
+
        itup->t_tid = *ht_ctid;

        /*
@@ -212,7 +221,11 @@ hashgettuple(PG_FUNCTION_ARGS)
        bool            res;

        /* Hash indexes are never lossy (at the moment anyway) */
-       scan->xs_recheck = false;
+#ifdef HASHVALUE_ONLY
+       scan->xs_recheck = true;
+#else
+       scan->xs_recheck = false;
+#endif

        /*
         * We hold pin but not lock on current buffer while outside the hash AM.
diff --git a/src/backend/access/hash/hashinsert.c
b/src/backend/access/hash/hashinsert.c
index 3eb226a..0800006 100644
--- a/src/backend/access/hash/hashinsert.c
+++ b/src/backend/access/hash/hashinsert.c
@@ -52,9 +52,15 @@ _hash_doinsert(Relation rel, IndexTuple itup)
         */
        if (rel->rd_rel->relnatts != 1)
                elog(ERROR, "hash indexes support only one index key");
+#ifdef HASHVALUE_ONLY
+       datum = index_getattr(itup, 1, _create_hash_desc(), &isnull);
+       Assert(!isnull);
+    hashkey = DatumGetUInt32(datum);
+#else
        datum = index_getattr(itup, 1, RelationGetDescr(rel), &isnull);
        Assert(!isnull);
        hashkey = _hash_datum2hashkey(rel, datum);
+#endif

        /* compute item size too */
        itemsz = IndexTupleDSize(*itup);
diff --git a/src/backend/access/hash/hashpage.c
b/src/backend/access/hash/hashpage.c
index b0b5874..bba64c4 100644
--- a/src/backend/access/hash/hashpage.c
+++ b/src/backend/access/hash/hashpage.c
@@ -785,7 +785,12 @@ _hash_splitbucket(Relation rel,
        OffsetNumber omaxoffnum;
        Page            opage;
        Page            npage;
-       TupleDesc       itupdesc = RelationGetDescr(rel);
+       TupleDesc       itupdesc;
+#ifdef HASHVALUE_ONLY
+    itupdesc = _create_hash_desc();
+#else
+    itupdesc = RelationGetDescr(rel);
+#endif

        /*
         * It should be okay to simultaneously write-lock pages from each 
bucket,
@@ -854,9 +859,13 @@ _hash_splitbucket(Relation rel,
                itup = (IndexTuple) PageGetItem(opage, PageGetItemId(opage, 
ooffnum));
                datum = index_getattr(itup, 1, itupdesc, &null);
                Assert(!null);
-
+#ifdef HASHVALUE_ONLY
+               bucket = _hash_hashkey2bucket(DatumGetUInt32(datum),
+                                                                         
maxbucket, highmask, lowmask);
+#else
                bucket = _hash_hashkey2bucket(_hash_datum2hashkey(rel, datum),
                                                                          
maxbucket, highmask, lowmask);
+#endif

                if (bucket == nbucket)
                {
diff --git a/src/backend/access/hash/hashsearch.c
b/src/backend/access/hash/hashsearch.c
index 258526b..5211e67 100644
--- a/src/backend/access/hash/hashsearch.c
+++ b/src/backend/access/hash/hashsearch.c
@@ -178,6 +178,7 @@ _hash_first(IndexScanDesc scan, ScanDirection dir)
                hashkey = _hash_datum2hashkey_type(rel, cur->sk_argument,
                                                                                
   cur->sk_subtype);

+    so->hashso_sk_hash = hashkey;
        /*
         * Acquire shared split lock so we can compute the target bucket safely
         * (see README).
diff --git a/src/backend/access/hash/hashutil.c
b/src/backend/access/hash/hashutil.c
index 41e2eef..81c6829 100644
--- a/src/backend/access/hash/hashutil.c
+++ b/src/backend/access/hash/hashutil.c
@@ -20,7 +20,7 @@
 #include "executor/execdebug.h"
 #include "storage/bufmgr.h"
 #include "utils/lsyscache.h"
-
+#include "catalog/pg_type.h"

 /*
  * _hash_checkqual -- does the index tuple satisfy the scan conditions?
@@ -28,16 +28,31 @@
 bool
 _hash_checkqual(IndexScanDesc scan, IndexTuple itup)
 {
-       TupleDesc       tupdesc = RelationGetDescr(scan->indexRelation);
+       TupleDesc       tupdesc;
        ScanKey         key = scan->keyData;
        int                     scanKeySize = scan->numberOfKeys;
+    Datum              datum;
+    bool               isNull;
+    HashScanOpaque      so = scan->opaque;

        IncrIndexProcessed();

+#ifdef HASHVALUE_ONLY
+    tupdesc = _create_hash_desc();
+    datum = index_getattr(itup,
+                          key->sk_attno,
+                          tupdesc,
+                          &isNull);
+    if( so->hashso_sk_hash != DatumGetUInt32(datum) )
+        return false;
+    key++;
+    scanKeySize--;
+#else
+    tupdesc = RelationGetDescr(scan->indexRelation);
+#endif
+
        while (scanKeySize > 0)
        {
-               Datum           datum;
-               bool            isNull;
                Datum           test;

                datum = index_getattr(itup,
@@ -222,3 +237,31 @@ hashoptions(PG_FUNCTION_ARGS)
                PG_RETURN_BYTEA_P(result);
        PG_RETURN_NULL();
 }
+
+/*
+ * _create_hash_desc - create a hash TupleDesc
+ *
+ * the TupleDesc is with int32 attribute, not uint32 because we've no
pg_type with UINT4OID
+ */
+TupleDesc _create_hash_desc()
+{
+    TupleDesc tupdesc = CreateTemplateTupleDesc(1, false);
+    TupleDescInitEntry(tupdesc, 1, "hashcode", INT4OID, -1, 0);
+    return tupdesc;
+}
+
+/*
+ * _hash_form_tuple - form a tuple with hash code only
+ */
+IndexTuple _hash_form_tuple(Relation rel, Datum* values, bool* isnull)
+{
+    TupleDesc       hashdesc;
+    IndexTuple      itup;
+    uint32          hashkey;
+
+    hashdesc = _create_hash_desc();
+    hashkey = _hash_datum2hashkey(rel, values[0]);
+    values[0] = UInt32GetDatum(hashkey);
+    itup = index_form_tuple(hashdesc, values, isnull);
+    return itup;
+}
diff --git a/src/include/access/hash.h b/src/include/access/hash.h
index ab0824d..141f1fc 100644
--- a/src/include/access/hash.h
+++ b/src/include/access/hash.h
@@ -100,6 +100,8 @@ typedef struct HashScanOpaqueData
        /* Current and marked position of the scan */
        ItemPointerData hashso_curpos;
        ItemPointerData hashso_mrkpos;
+    /* Hash value of the scan key */
+    uint32      hashso_sk_hash;
 } HashScanOpaqueData;

 typedef HashScanOpaqueData *HashScanOpaque;
@@ -227,6 +229,10 @@ typedef HashMetaPageData *HashMetaPage;
  */
 #define HASHPROC               1

+/*
+ * store hash value only in the bucket
+ */
+#define HASHVALUE_ONLY

 /* public routines */

@@ -330,6 +336,8 @@ extern Bucket _hash_hashkey2bucket(uint32 hashkey,
uint32 maxbucket,
                                         uint32 highmask, uint32 lowmask);
 extern uint32 _hash_log2(uint32 num);
 extern void _hash_checkpage(Relation rel, Buffer buf, int flags);
+extern TupleDesc _create_hash_desc();
+extern IndexTuple _hash_form_tuple(Relation rel, Datum* values, bool* isnull);

 /* hash.c */
 extern void hash_redo(XLogRecPtr lsn, XLogRecord *record);


-- 
Best Regards,
Xiao Meng

DKERC, Harbin Institute of Technology, China
Gtalk: [EMAIL PROTECTED]
MSN: [EMAIL PROTECTED]
http://xiaomeng.yo2.cn
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index 6a5c000..1a8dc75 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -129,7 +129,11 @@ hashbuildCallback(Relation index,
 	IndexTuple	itup;
 
 	/* form an index tuple and point it at the heap tuple */
+#ifdef HASHVALUE_ONLY
+    itup = _hash_form_tuple(index, values,isnull);
+#else
 	itup = index_form_tuple(RelationGetDescr(index), values, isnull);
+#endif
 	itup->t_tid = htup->t_self;
 
 	/* Hash indexes don't index nulls, see notes in hashinsert */
@@ -171,7 +175,12 @@ hashinsert(PG_FUNCTION_ARGS)
 	IndexTuple	itup;
 
 	/* generate an index tuple */
+#ifdef HASHVALUE_ONLY
+    itup = _hash_form_tuple(rel, values, isnull);
+#else
 	itup = index_form_tuple(RelationGetDescr(rel), values, isnull);
+#endif
+
 	itup->t_tid = *ht_ctid;
 
 	/*
@@ -212,7 +221,11 @@ hashgettuple(PG_FUNCTION_ARGS)
 	bool		res;
 
 	/* Hash indexes are never lossy (at the moment anyway) */
-	scan->xs_recheck = false;
+#ifdef HASHVALUE_ONLY
+	scan->xs_recheck = true;
+#else
+ 	scan->xs_recheck = false;
+#endif
 
 	/*
 	 * We hold pin but not lock on current buffer while outside the hash AM.
diff --git a/src/backend/access/hash/hashinsert.c b/src/backend/access/hash/hashinsert.c
index 3eb226a..0800006 100644
--- a/src/backend/access/hash/hashinsert.c
+++ b/src/backend/access/hash/hashinsert.c
@@ -52,9 +52,15 @@ _hash_doinsert(Relation rel, IndexTuple itup)
 	 */
 	if (rel->rd_rel->relnatts != 1)
 		elog(ERROR, "hash indexes support only one index key");
+#ifdef HASHVALUE_ONLY
+	datum = index_getattr(itup, 1, _create_hash_desc(), &isnull);
+	Assert(!isnull);
+    hashkey = DatumGetUInt32(datum);
+#else
 	datum = index_getattr(itup, 1, RelationGetDescr(rel), &isnull);
 	Assert(!isnull);
 	hashkey = _hash_datum2hashkey(rel, datum);
+#endif
 
 	/* compute item size too */
 	itemsz = IndexTupleDSize(*itup);
diff --git a/src/backend/access/hash/hashpage.c b/src/backend/access/hash/hashpage.c
index b0b5874..bba64c4 100644
--- a/src/backend/access/hash/hashpage.c
+++ b/src/backend/access/hash/hashpage.c
@@ -785,7 +785,12 @@ _hash_splitbucket(Relation rel,
 	OffsetNumber omaxoffnum;
 	Page		opage;
 	Page		npage;
-	TupleDesc	itupdesc = RelationGetDescr(rel);
+	TupleDesc	itupdesc;
+#ifdef HASHVALUE_ONLY 
+    itupdesc = _create_hash_desc();
+#else
+    itupdesc = RelationGetDescr(rel);
+#endif
 
 	/*
 	 * It should be okay to simultaneously write-lock pages from each bucket,
@@ -854,9 +859,13 @@ _hash_splitbucket(Relation rel,
 		itup = (IndexTuple) PageGetItem(opage, PageGetItemId(opage, ooffnum));
 		datum = index_getattr(itup, 1, itupdesc, &null);
 		Assert(!null);
-
+#ifdef HASHVALUE_ONLY
+		bucket = _hash_hashkey2bucket(DatumGetUInt32(datum),
+									  maxbucket, highmask, lowmask);
+#else
 		bucket = _hash_hashkey2bucket(_hash_datum2hashkey(rel, datum),
 									  maxbucket, highmask, lowmask);
+#endif
 
 		if (bucket == nbucket)
 		{
diff --git a/src/backend/access/hash/hashsearch.c b/src/backend/access/hash/hashsearch.c
index 258526b..5211e67 100644
--- a/src/backend/access/hash/hashsearch.c
+++ b/src/backend/access/hash/hashsearch.c
@@ -178,6 +178,7 @@ _hash_first(IndexScanDesc scan, ScanDirection dir)
 		hashkey = _hash_datum2hashkey_type(rel, cur->sk_argument,
 										   cur->sk_subtype);
 
+    so->hashso_sk_hash = hashkey;
 	/*
 	 * Acquire shared split lock so we can compute the target bucket safely
 	 * (see README).
diff --git a/src/backend/access/hash/hashutil.c b/src/backend/access/hash/hashutil.c
index 41e2eef..81c6829 100644
--- a/src/backend/access/hash/hashutil.c
+++ b/src/backend/access/hash/hashutil.c
@@ -20,7 +20,7 @@
 #include "executor/execdebug.h"
 #include "storage/bufmgr.h"
 #include "utils/lsyscache.h"
-
+#include "catalog/pg_type.h"
 
 /*
  * _hash_checkqual -- does the index tuple satisfy the scan conditions?
@@ -28,16 +28,31 @@
 bool
 _hash_checkqual(IndexScanDesc scan, IndexTuple itup)
 {
-	TupleDesc	tupdesc = RelationGetDescr(scan->indexRelation);
+	TupleDesc	tupdesc; 
 	ScanKey		key = scan->keyData;
 	int			scanKeySize = scan->numberOfKeys;
+    Datum		datum;
+    bool		isNull;
+    HashScanOpaque      so = scan->opaque;
 
 	IncrIndexProcessed();
 
+#ifdef HASHVALUE_ONLY
+    tupdesc = _create_hash_desc();
+    datum = index_getattr(itup,
+                          key->sk_attno, 
+                          tupdesc, 
+                          &isNull);
+    if( so->hashso_sk_hash != DatumGetUInt32(datum) )
+        return false;
+    key++;
+    scanKeySize--;
+#else
+    tupdesc = RelationGetDescr(scan->indexRelation);
+#endif
+
 	while (scanKeySize > 0)
 	{
-		Datum		datum;
-		bool		isNull;
 		Datum		test;
 
 		datum = index_getattr(itup,
@@ -222,3 +237,31 @@ hashoptions(PG_FUNCTION_ARGS)
 		PG_RETURN_BYTEA_P(result);
 	PG_RETURN_NULL();
 }
+
+/*
+ * _create_hash_desc - create a hash TupleDesc
+ *
+ * the TupleDesc is with int32 attribute, not uint32 because we've no pg_type with UINT4OID
+ */
+TupleDesc _create_hash_desc()
+{
+    TupleDesc tupdesc = CreateTemplateTupleDesc(1, false);
+    TupleDescInitEntry(tupdesc, 1, "hashcode", INT4OID, -1, 0);
+    return tupdesc;
+}
+
+/*
+ * _hash_form_tuple - form a tuple with hash code only 
+ */
+IndexTuple _hash_form_tuple(Relation rel, Datum* values, bool* isnull)
+{
+    TupleDesc       hashdesc;
+    IndexTuple      itup;
+    uint32          hashkey;
+
+    hashdesc = _create_hash_desc();
+    hashkey = _hash_datum2hashkey(rel, values[0]);
+    values[0] = UInt32GetDatum(hashkey);
+    itup = index_form_tuple(hashdesc, values, isnull);
+    return itup;
+}
diff --git a/src/include/access/hash.h b/src/include/access/hash.h
index ab0824d..141f1fc 100644
--- a/src/include/access/hash.h
+++ b/src/include/access/hash.h
@@ -100,6 +100,8 @@ typedef struct HashScanOpaqueData
 	/* Current and marked position of the scan */
 	ItemPointerData hashso_curpos;
 	ItemPointerData hashso_mrkpos;
+    /* Hash value of the scan key */
+    uint32      hashso_sk_hash;
 } HashScanOpaqueData;
 
 typedef HashScanOpaqueData *HashScanOpaque;
@@ -227,6 +229,10 @@ typedef HashMetaPageData *HashMetaPage;
  */
 #define HASHPROC		1
 
+/*
+ * store hash value only in the bucket
+ */
+#define HASHVALUE_ONLY
 
 /* public routines */
 
@@ -330,6 +336,8 @@ extern Bucket _hash_hashkey2bucket(uint32 hashkey, uint32 maxbucket,
 					 uint32 highmask, uint32 lowmask);
 extern uint32 _hash_log2(uint32 num);
 extern void _hash_checkpage(Relation rel, Buffer buf, int flags);
+extern TupleDesc _create_hash_desc();
+extern IndexTuple _hash_form_tuple(Relation rel, Datum* values, bool* isnull);
 
 /* hash.c */
 extern void hash_redo(XLogRecPtr lsn, XLogRecord *record);
-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

Reply via email to